Isostructural replacement of zinc by cadmium in bacterial metallothionein

Claudia Blindauer, Mark Harrison, John Parkinson, Nigel Robinson, Peter Sadler

Research output: Contribution to journalArticle

Abstract

Abstract: The class II metallothionein SmtA from the cyanobacterium Synechococcus PCC 7942 plays a major role in providing tolerance to high levels of zinc as well as a lesser role in cadmium detoxification. We previously determined the NMR structure of Zn(4)SmtA [Blindauer et al., PNAS 2001, 98, 9593-9598] and assessed its zinc-binding dynamics. In the present report, we discuss the solution structure of cadmium-loaded SmtA and provide insight into the way in which cyanobacteria manage chemically similar toxic and essential metal ions. Comparisons of 3D structures and NMR data indicate that SmtA is able to accommodate either zinc or cadmium equally well. This work is not only relevant to understanding the biological role of bacterial metallothioneins, but also has implications for metalloprotein promiscuity and specificity.
Original languageEnglish
Pages (from-to)167-173
Number of pages7
JournalMetal Ions in Biology and Medicine
Volume10
Publication statusPublished - 2008
Event10th International Symposium on Metal Ions in Biology and Medicine - Bastia, France
Duration: 19 May 200822 May 2008

Keywords

  • zinc
  • cadmium
  • detoxification
  • metal-ions
  • cyanobacteria
  • binding
  • locus

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